Kentucky Derby-winning trainer Rick Dutrow Jr. has asked New York’s top court to overturn his 10-year ban by the state Racing and Wagering Board, saying it raises substantial civil rights issues.

In requesting the Court of Appeals to hear Dutrow’s case, attorney Michael Koenig said the judges should decide whether the appearance of bias by racing board Chairman John Sabini cost the trainer his right to a fair proceeding over drug violations. In court papers, he said Sabini had a conflicting role as an officer of the Association of Racing Commissioners International, which advocated revoking Dutrow’s license.

A midlevel New York court in July court upheld the ban. State lawyers noted that the midlevel court found no evidence of actual bias, urging the top court to reject taking Dutrow’s case.

“In the absence of any proof that the chairman was biased and that the determination flowed from that bias, petitioner did not establish that he was deprived of a fair hearing,” Assistant Solicitor General Kathleen Arnold wrote. She also said allegations Dutrow’s punishment was “based on vindictiveness,” and that the midlevel Appellate Division failed to substantially address that, is not a constitutional question.

Meanwhile, Dutrow has continued working with his punishment stayed while Koenig pursues the appeal. In August, his colt Willy Beamin won the $150,000 Albany Stakes at Saratoga Race Course for 3-year-olds bred in New York. Three days later, Willy Beamin ran down the leaders in the stretch for a surprising win in the $500,000 King’s Bishop.

“The substantial constitutional question that emerges on this appeal is the proper legal standard to be applied when challenging a quasi-judicial decision maker’s impartiality under the due process clauses of the New York State and U.S. Constitutions,” Koenig wrote. “This court has repeatedly said ‘an impartial decision maker is a core guarantee of due process, fully applicable to adjudicatory proceedings before administrative agencies.”

Koenig said his client initially faced only a 90-day suspension in early 2011, which was immediately appealed, and two weeks later the racing board proposed turning it into a lifetime ban. In the meantime, he said Sabini had received emails from the racing commissioners association, where he was secretary and treasurer, including one noting that the staff of “an influential U.S. senator” said the 90-day suspension seemed like a “light penalty.”

The three-member racing board in October cited infractions including syringes containing a painkiller and sedative found in Dutrow’s desk and the painkiller butorphanol, an opioid analgesic, found in the urine of his horse Fastus Cactus in November 2010, after it won at Aqueduct Racetrack. The board also fined him $50,000.

The trainer had told a hearing officer that he didn’t know how the syringes got into his desk. A blood test of Fastus Cactus didn’t show any butorphanol, and Dutrow’s expert witness theorized that the urine test might have been contaminated. He faced brief New York suspensions for drug violations in 2003, 2004 and 2008.

Dutrow’s subsequent 10-year ban is among the board’s harshest penalties, second only to the lifetime ban in 2009 of breeder Ernie Paragallo after malnourished horses were found at his Hudson Valley farm.

Dutrow trained Big Brown to Derby and Preakness wins in 2008. He was refused a license to race in Kentucky last year. He was the leading trainer at this year’s spring-summer Belmont meet with 27 winners, according to the New York Racing Association.

The decision by the seven-member Court of Appeals whether to hear Dutrow’s case is expected in October.